CVE-2026-72243 (GCVE-0-2026-72243)
Vulnerability from cvelistv5 – Published: 2026-08-15 05:54 – Updated: 2026-10-16 18:45
VLAI
EPSS
VEX
Title
selinux: check connect-related permissions on TCP Fast Open
Summary
In the Linux kernel, the following vulnerability has been resolved:
selinux: check connect-related permissions on TCP Fast Open
Similar to Landlock, SELinux was not updated when TCP Fast Open
support was introduced to ensure connect-related permissions are
checked when using TCP Fast Open. Update its socket_sendmsg() hook to
call selinux_socket_connect() when MSG_FASTOPEN is passed.
Severity
8.4 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-16 18:44 UTC
Assigner
References
6 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
cf60af03ca4e71134206809ea892e49b92a88896 , < 11406d0d7e11b4e525bb2ace2c70107031d058da
(git)
Affected: cf60af03ca4e71134206809ea892e49b92a88896 , < e507633bf76bccf1a6af27771fb0d6e2862b7eac (git) Affected: cf60af03ca4e71134206809ea892e49b92a88896 , < d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3 (git) Affected: cf60af03ca4e71134206809ea892e49b92a88896 , < fc633a598206d4f23af782db7c0b5f3a82751d2c (git) Affected: cf60af03ca4e71134206809ea892e49b92a88896 , < 646ebbc5f2ff9147d084e1213143f091026a611c (git) Affected: cf60af03ca4e71134206809ea892e49b92a88896 , < 44c74d27d1b9aaa99fa8a83640c1223575262b80 (git) |
guessed | |
| Linux | Linux |
Affected:
3.6
Unaffected: 0 , < 3.6 (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-72243",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-16T18:44:53.438037Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-16T18:45:04.616Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"security/selinux/hooks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "11406d0d7e11b4e525bb2ace2c70107031d058da",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "e507633bf76bccf1a6af27771fb0d6e2862b7eac",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "fc633a598206d4f23af782db7c0b5f3a82751d2c",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "646ebbc5f2ff9147d084e1213143f091026a611c",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "44c74d27d1b9aaa99fa8a83640c1223575262b80",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"security/selinux/hooks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.6"
},
{
"lessThan": "3.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.178",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.145",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.97",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "3.6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nselinux: check connect-related permissions on TCP Fast Open\n\nSimilar to Landlock, SELinux was not updated when TCP Fast Open\nsupport was introduced to ensure connect-related permissions are\nchecked when using TCP Fast Open. Update its socket_sendmsg() hook to\ncall selinux_socket_connect() when MSG_FASTOPEN is passed."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.4,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Exploitation requires a confined local process to invoke sendmsg(2)/sendto(2) with MSG_FASTOPEN; the vulnerable selinux_socket_sendmsg() LSM hook runs on the syscall path before TCP fast-open performs its implicit connect.\nAC:L - A confined task with SOCKET__WRITE can reliably trigger the bypass with one sendmsg/sendto using MSG_FASTOPEN and a destination address; TFO client is enabled by default (sysctl_tcp_fastopen=TFO_CLIENT_ENABLE) and no race or special victim state is needed.\nPR:L - The attacker must be an unprivileged process in a SELinux domain that grants socket write but denies connect/name_connect (e.g., confined Android apps, container workloads, hardened service domains); no real root or init-namespace privileges are required.\nUI:N - No victim interaction is required; the confined attacker process directly issues the bypassing syscall without needing another user or administrator to perform any action.\nS:C - Successful exploitation crosses the SELinux MAC confinement boundary, allowing a sandboxed domain to establish outbound TCP/MPTCP connections that connect(2) and name_connect policy would have blocked, escaping the intended network policy scope.\nC:H - Bypassing connect and name_connect mediation lets a confined process open TCP/MPTCP sessions to SELinux-forbidden destinations and read arbitrary response data from those services (internal APIs, metadata endpoints, databases), constituting unauthorized information disclosure.\nI:H - The bypass enables unauthorized outbound connection establishment and transmission of arbitrary application data (including SYN-cookie payload) to hosts and ports explicitly denied by SELinux connect/name_connect rules, violating integrity of the confinement policy.\nA:N - This is a pure SELinux LSM policy-bypass flaw with no kernel memory corruption, panic, oops, hang, or resource exhaustion; exploitation does not impact system availability."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-18T06:56:32.099Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/11406d0d7e11b4e525bb2ace2c70107031d058da"
},
{
"url": "https://git.kernel.org/stable/c/e507633bf76bccf1a6af27771fb0d6e2862b7eac"
},
{
"url": "https://git.kernel.org/stable/c/d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3"
},
{
"url": "https://git.kernel.org/stable/c/fc633a598206d4f23af782db7c0b5f3a82751d2c"
},
{
"url": "https://git.kernel.org/stable/c/646ebbc5f2ff9147d084e1213143f091026a611c"
},
{
"url": "https://git.kernel.org/stable/c/44c74d27d1b9aaa99fa8a83640c1223575262b80"
}
],
"title": "selinux: check connect-related permissions on TCP Fast Open",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72243",
"datePublished": "2026-08-15T05:54:31.117Z",
"dateReserved": "2026-08-09T03:40:39.914Z",
"dateUpdated": "2026-10-16T18:45:04.616Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-72243",
"date": "2026-10-20",
"epss": "0.00166",
"percentile": "0.05451"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"security/selinux/hooks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "11406d0d7e11b4e525bb2ace2c70107031d058da",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "e507633bf76bccf1a6af27771fb0d6e2862b7eac",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "fc633a598206d4f23af782db7c0b5f3a82751d2c",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "646ebbc5f2ff9147d084e1213143f091026a611c",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "44c74d27d1b9aaa99fa8a83640c1223575262b80",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"security/selinux/hooks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.6"
},
{
"lessThan": "3.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nselinux: check connect-related permissions on TCP Fast Open\n\nSimilar to Landlock, SELinux was not updated when TCP Fast Open\nsupport was introduced to ensure connect-related permissions are\nchecked when using TCP Fast Open. Update its socket_sendmsg() hook to\ncall selinux_socket_connect() when MSG_FASTOPEN is passed."
}
],
"id": "CVE-2026-72243",
"lastModified": "2026-10-16T19:17:16.370",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "NONE",
"baseScore": 8.4,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
"version": "3.1"
},
"exploitabilityScore": 2.0,
"impactScore": 5.8,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-72243",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-16T18:44:53.438037Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-15T06:21:51.443",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/11406d0d7e11b4e525bb2ace2c70107031d058da"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/44c74d27d1b9aaa99fa8a83640c1223575262b80"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/646ebbc5f2ff9147d084e1213143f091026a611c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e507633bf76bccf1a6af27771fb0d6e2862b7eac"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fc633a598206d4f23af782db7c0b5f3a82751d2c"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-10-12T14:31:31+00:00",
"cve": "CVE-2026-72243",
"id": "CVE-2026-72243",
"initial_release_date": "2026-08-15T00:00:00+00:00",
"product_status:fixed": "612",
"product_status:known_affected": "98",
"product_status:known_not_affected": "14",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: selinux: check connect-related permissions on TCP Fast Open",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72243.json",
"version": "3"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.